Jamming Detection

The library reports RF interference and jamming information per frequency band via UBX-MON-RF.

Jamming States

State	Meaning
`Unknown`	Jamming detection not available
`OK — No Significant Jamming`	Clean signal, no interference
`Warning — Interference Visible But Fix OK`	Some interference, positioning still works
`Critical — Interference Visible And No Fix`	Severe jamming, fix lost

Reading RF Data

C++

auto nav = hat->waitAndGetFreshNavigation();
for (const auto& rf : nav.rfBlocks)
{
    printf("Band: %s\n", Utils::eBand2string(rf.gnssBand).c_str());
    printf("  Jamming: %s\n", Utils::jammingState2string(rf.jammingState).c_str());
    printf("  Antenna: %s (power: %s)\n",
        Utils::antennaStatus2string(rf.antennaStatus).c_str(),
        Utils::antennaPower2string(rf.antennaPower).c_str());
    printf("  Noise: %u/ms, AGC: %.1f%%, CW: %.1f dB\n",
        rf.noisePerMS, rf.agcMonitor, rf.cwInterferenceSuppressionLevel);
}

Python

nav = hat.wait_and_get_fresh_navigation()
for rf in nav.rf_blocks:
    print(f"Jamming: {rf.jamming_state}")
    print(f"Antenna: {rf.antenna_status} (power: {rf.antenna_power})")
    print(f"Noise: {rf.noise_per_ms}/ms, AGC: {rf.agc_monitor:.1f}%")

Interpreting the Data

AGC Monitor

Normal: ~50–70% — healthy signal levels
Low (<30%): Strong signal or interference saturating the front end
High (>80%): Weak signal, possible antenna issue

Antenna Diagnostics

Status	Meaning	Action
`OK`	Antenna connected and working	Normal
`Open`	No antenna detected	Check connector
`Short`	Short circuit on antenna line	Replace cable/antenna
`Init` / `DontKnow`	Detection not complete	Wait for fix